Brush



- March 29, 1949.

R. o. PETERSON TAL BRUSHES Filed Now 22, .1943

. INVENTORS RUBEN OPETERSON and VERNON K. CHARVAT "Patented Mar. 29, 1949 BRUSH Ruben 0. Peterson, University Heights, and Vernon K. Charvat, Lakewood, Ohio, assignors to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application November 22, 1943, Serial No. 511,256

13 Claims. (Cl. -206) The present improvements, relating as indicated to brushes, have more particular regard to brushes of the twisted stem type, i. e. brushes in which the bristles or equivalent stranded brush material is secured between a plurality of parallel disposed wires which are then twisted about a common aXis with the result that such brush material is disposed in the form of a helix about the resulting twisted stem.

Such brushes have long been used in certain fields as for cleaning bottles, test tubes, and the like, and also as components in other types of brushes. However, such twisted stem type of brush has never per se figured largely in industrial or shop uses, as for cleaning and polishing metal parts. One reason for this is that while the brush material may be quite firmly gripped between the twisted wires that form the stem, the latter have only in effect a line contact with the sides of the material so that such material is subject under hard conditions of service to undue concentration of fiexure with consequent rapid deterioration, particularly where wire strands form the material. It has also been found difiicult to secure a sufiicient body of the brush material between the wires of the stem so as to provide a brush capable of efiective cleaning or polishing action in contact with metal parts.

One object of the present invention, accordingly, is to provide a twisted stem type of brush in which a heavier layer of brush material may be utilized and at the same time such material so held as to avoid concentration of bending action to a line contact between the wires and such material. We have also discovered that by suitably modifyin the construction of the stem a very effective end brush, suitable for use in cleaning and polishing holes, may be made in the same manner.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means and elements hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain structure embodying the invention, such disclosed elements constituting, however, but one of various structural forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 is a side elevation of a twisted stem brush of more or less conventional form but embodyingcertain of our present improvements;

Fig. 2 is a transverse section of such brush, the

2 plane of the section being indicated by the line 22, Fig. 1;

Fig. 3 is a side elevation of a modified construction of our improved brush;

Fig. 4 is a transverse section of such modified construction, the plane of the section being indicated by the line 4-4, Fig. 3;

Fig. 5 is a side elevation of still a third form of our brush;

Fig. 6 illustrates such latter form in combination with a specially designed holder or mounting therefor;

Fig. '7 is a central sectional view of amodified form of holder adapted to receive brushes embodying our improved construction, more particularly of the form illustrated in Figs. 3 and 4;

Fig. 8 is an end view of such holder; and

Figs. 9 and 10 illustrate more or less diagrammatically the manner in which the modified forms of our brush as shown in Figs. 3 and 5 may be assembled.

In the first form of twisted stem brush, that illustrated in Figs. 1 and 2, the brush material i comprises as usual a layer of stranded brush material such as bristles or fine wires uniformly disposed between the two parallel wires 2 which constitute the stem. Such wires will ordinarily consist of the doubled portions of a single wire, the point 3 at which the latter is rebent upon itself constituting the one end of the brush proper. Ordinarily the twisted wires 2 extend for some distance beyond the other end of the brush proper,

constituting a stem or handle whereby the brush may be mounted or manipulated as desired.

As clearly shown in Fig. 2, the wires 2 between which the brush material is thus held are of halfround section with their fiat faces opposed and it is between such half faces that the layer of brush material I is secured. Such relationship of the fiat wire faces Will of course be maintained when the wires are twisted to form the finished brush. Accordingly, the layer of brush material is transversely supported at its central portion for a distance equal to the width of the stem wires, with the result not only that such material is much more firmly attached to the stem than where the latter is formed of ordinary round wire, but the layer of such material will be relatively compact, i. e. not tend to flare widely at its respective outer edges.

There is thus produced in counterdistinction to the ordinary twisted stem wire brush, in which the face of the brush is of more or less cylindrical form, a brush in which the face takes the form of two closely defined helices consisting" would be loosely held and easily shed during the operation of the brush. Accordingly in the manufacture of our improved brush, following insertion of the layer of brush material between the wires, the portions of the latter which overlie such layer are forcibly pressed together, as between dies, and such pressure released only after the remaining portions of the wires have been twisted. In deed, in the case of a long brush, such pressure may be released by stages as the twisting operation progresses. example, be compressed by pressures on the order of 10,000 to 20,000 lbs/sq. in. or more, a wire re taining member which may have a tensile strength of only 100 lbs. will generally be of sufficient strength to retain such material in substantially such compressed condition although the retaining member obviously would have pulled apart if it had been attempted to compact such material to any such degree through tightening of such member about such material.

Once such material is thus compressed it tends to retain its compacted form since much of the heavy pressure employed was necessary to do the work of deforming the components of such material and to overcome frictional resistance of such components relative to each other.

While in the construction of brush just described and illustrated in Fig. 1, the layer of brush material is inserted beginning at the rebent end 3 of wires 2, it will be understood that such layer may start at a point removed from such end so that the twisting of the wires will provide an extension beyond the respective ends of the helically disposed layer of brush material as found in the finished brush.

In counterdistinction to the conventional twisted wire brush in which the stem wires have only a line contact with the layer of brush material, which concentrates the fiexure stresses on the individual strands at substantially the same point, the use of stem wires having fiat contacting faces not only increases the area of contact and so retains the brush material more securely against dislodgement, but two points of flexure instead of one are established for the individual strands. As the brush is rotated in use the stresses in the brush material produced by pressing the ends of the strands against the work-piece originate from both ends; accordingly, by thus separating the point of stress concentration for any given brush element into two points spaced a substantial distance apart, the number of stress cycles on any such point in a given time will be only one-half the number occurring where the brush material has a single line of contact with the stem wires. As a result, measuring the fatigue strength of the brush material by a given number of cycles, it is obvious that the time before fatigue failure will occur in our improved construction of brush will be twice that of the conventional twisted stem brush, i. e. the useful life of the brush is in effect doubled.

The use of such half-round or fiat-sided wire in the construction of a brush of the twisted stem type also lends itself admirably to the production If crimped brush material, for u of the new and distinctive form of brush illustrated in Figs. 3 and 5, which are intended pr1ncipally for use in operations that require light brushing action on the side walls of holes, cavities and recesses of small diameter. The limitations of the twisted wire brush where the brush material is spirally disposed do not permit the use of enough well supported material to secure brushing action adequate to accomplish the required results.

Referring first to the modification illustrated in Fig. 3 and in section in Fig. 4, it will be noted that just as in the first described construction, half-round wire 5 or the doubled portions of a single wire of half-round construction are twisted together to form the stem of the brush. However, instead of inserting the layer of brush material 5 between such intertwisted wires with resultant helical disposition of the brush material, the latter is inserted only adjacent the end or point 1 where the component wires of the stem are doubled on each other, and the twisting of the wires begins beyond, but immediately adjacent, such inserted brush material. In other words, the sections 5a of the wires 5 between which the brush material is held are not only parallel but straight and the brush material projects on opposite sides therefrom in corresponding straight form. In other words, such brush material extends through and crosswise of the stem in the form of a flat tuft.

The brush shown in Fig. 5 is of identically the same construction as that just described in connection with the showing of Figs. 3 and 4 except 1 that the layer of brush material 8 instead of having parallel edges is trimmed to present edges sloping toward the point 5 which forms the end of the brush. Otherwise stated, the layer of brush material is of generally triangular form which adapts the brush particularly for operation in conical cavities as in cleaning and finishing countersunk holes in metal parts.

This last described form of brush will desirably be mounted in a holder 9 as illustrated in Fig. 6, such holder having a bore [0 adapted to receive the twisted stem of the brush and having its forward end ll tapered to correspond with the angular slope of the edges of the inserted brush material 8. Such tapered end of the holder is furthermore transversely slotted so that the brush material may be received therein with its edges projecting a short distance beyond. The sides of the slot will thus support such edges and prevent the brush material from being unduly spread apart when the brush is in use.

For certain uses, the form of our improved brush illustrated in Figs. 3 and 4 may also be advantageously mounted in a holder similar to that illustrated in Fig. 6. In such case the forward end of the holder instead of being tapered will be cylindrical to conform with the shape of the layer of brush material 6.

It will be understood that the edges of the brush layer in addition to being trimmed along parallel lines, as illustrated in Fig. 3, or along converging lines, as illustrated in Fig. 5, may be trimmed to present any desired contour so as to conform with the contour of the surface of the work-piece being brushed.

still another form of holder may be advantageously employed in conjunction with the particular construction of brush thus shown in Figs. 3 and 4. As illustrated in Figs. 7 and 8, this form of holder comprises a hollow cylindrical body 20 open at one end and provided at the other with a central stud 2| whereby it may be secured in a chuck or otherwise mounted for rotative movement about its axis. The body of the holder is provided with a plurality (six as shown) of bores 22 disposed parallel to the axis and preferably equi-distantly spaced about the body, such bores being of a diameter to receive the twisted stems of a corresponding number of brushes of the form illustrated in Figs. 3 and 4. The lower edge of the holder is furthermore provided with radial slots 23 intersecting the bores 22 into which slots the layers of brush material carried by the respective stems are received with the outer ends of such layers projecting as shown.

The amount of brush material thus left projecting will depend upon the degree of flexibility which the brush material should have when in contact with the work. As illustrated in Fig. 7, this form of holder equipped with brushes in the manner described, is particularly adapted to operate on a work-piece such as a boss W located in a confined space. The individual brushes may be easily inserted and removed from the holder and may be either held therein by frictional engagement or, if desired, the ends of the stems may be allowed to project to the upper ends of the bores and be bent over. When one side of a brush becomes worn, its position in the bore and corresponding slot may be reversed and the life of the assembly thus doubled.

In addition to being adapted for mounting singly in a holder, as illustrated in Fig. 6, or in plural number in a holder such as illustrated in Figs. '7 and 8, this modified form of our improved brush is readily adapted for attachment to a manually operated handle, an extensionrod or flexible shaft, as the particular field of use may require.

The remaining figures, 9 and 10, of the drawing illustrate a preferred method and apparatus for making the modified form of our improved twisted wire stem brush shown in Figs. 3 and 5. In order that these brushes may withstand the severe work demanded of them, the layer of brush material inserted between the doubled end portions of the stem wires should be of a certain optimum thickness and at the same time closely compacted together. In order to accomplish these results, after inserting the layer 6 of such material (see Fig. '7) between the doubled portions of the wires 5 adjacent the po nt 1 at wh ch they are doubled, the proiecting portions of the wires which are to constitute the twisted stem are passed through an aperture I2 in a fixed abutment l3. Such wires are then pulled forcibly, i. e. to the right as shown in Fig. 8, so as to press the layer of brush material 6 against abutment l3 and crowd such material compactly into the space between the wires allotted to such material. Thereupon the adjacentportions of the wires 5 are forcibly pressed betweenv movable jaws l4 so as to laterally close such portions upon the layer of brush material and the portions of the wires 5 lying beyond abutment I3 are gripped as between rotary jaws l5 and tightly twisted together to form the stem of the brush. The method of manufacture just described it will be seen not only insures that the brush material will be securely held in desired form between the straight portions of the doubled stem wire, but also greatly facilitates the manufacture of the brush by reducing such manufacture to several relatively simple operaticns.

-Moreover such method of manufacture lends Figs. 9 and 10, i. e. the doubled wires are passedover the layer of brush material while the latter is suitably supported so as to engage the same at desired intervals, then the portions of the wires which lie beyond the layer are twisted while the latter is subjected to pressure between the wires both before and during such twisting operation. Finally, the layer of brush material is severed between successive pairs of the twisted stems which have been thus applied thereto, thus producing a corresponding series of individual brushes.

The layer of brush material may be of indefinite length, wound upon a reel from which it is drawn, as successive pairs of stem members are applied in the manner just described. In this way the even distribution of the brush material lengthwise of the finished brush is assured and since such material will be firmly secured between the stem wires before the layer is severed, the uniform sizing of the cut-off strands that are secured to such stem is likewise assured as well as their uniform and accurate placement transversely of the stem. This further improvement in the manufacture of brushes of the twisted stem type is equally adaptable to the making of brushes in which the brush material is retained in parallel relation as shown in Figs. 3 and 5, or disposed in the form of a helix as illustrated in Fig. 1. In case it is desired to make a brush of such twisted form, the twisting operation is merely continued to include the portions of the stem wires between which the brush material has been initially secured by the pressing or clamping step described above. While particularly advantageous in the manufacture of the flat form of brush, especially where, as will frequently be the case, the brush is quite small in size so that the insertion and handling of the material if previously cut into proper lengths becomes a very difiicult matter indeed, the clamping of the brush material fiatwise between the parallel disposed stem wires, constitutes an important advance in the manufacture of the fully twisted type of brush. In other words, the application of lateral pressure to the portions of the stem wires which contact the transversely disposed brush material, serves to compress and clamp such brush material so that it will not only remain in place during the twisting of the stem portions not in contact with the brush material, but be sufficiently securely held to permit cutting it to length, as well as to permit subsequent twisting of the portions of the stem Wires applied thereto, without disturbing the disposition of the material in the layer between the twisted stem wires in the finished brush.

It will be understood that while in the several illustrated forms of our improved brush the pairs of opposed elongated members which enter into the stem are constituted of a doubled wire, two separate members thus opposed may be twisted accuses together to form the stem, the twisting in such case being continued beyond the interposed brush material at both ends of the latter. For that matter where a doubled or rebent wire is employed, the interposed brush material may not extend to the point where the wire is thus doubled or rebent and the corresponding extending portions of such wire may be twisted together to form in effect a continuation of the stem. Aside from the advantageous results which, as previously noted, are obtained in the finished brush by the use of wires or equivalent members having flat opposed faces to hold the brush material, the use of such members contributes materially to the success of the method of manufacture hereinbefore described, in that the application of pressure to the interposed layer of brush material through such fiatfaced retaining members will not cut the material as would the round stem wires in current use.

Other forms may be employed embodying the features of our invention instead of the one here explained, change being made in the form or construction, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by our preferred method or by others embodying steps equivalent to those stated in the following claims.

We therefore particularly point out and distinctly claim as our invention:

1. In the manufacture of brushes of the twisted stem type, the steps which include placing a layer of stranded brush material between opposed stem elements, applying pressure to such elements so as to leave such layer laterally compressed and clamped therebetween, preliminarily to twisting such elements, then twisting together the portions of such elements lying beyond such layer, and then extendin such twisting to include the portions of said elements between which such layer is thus clamped.

2. A brush comprising a stem formed of a doubled wire having a flat face, the doubled portions having their flat faces opposed and being twisted together to form a stem except for a limited extent adjacent the point of doubling, where such wire portions are left in straight, closely pressed, parallel relation, and a layer of substantially straight, self-sustaining, stranded brush material interposed and held tightly clamped between the faces of such straight, parallel wire portions, the component strands being disposed in substantially parallel relation transversely of such clamping wire portions.

3. A brush comprising a stem formed of a doubled wire having a flat face, the doubled portions havin their fiat faces opposed and being twisted together to form a stem except for a limited extent adjacent the point of doubling, where such wire portions are left in straight, closely pressed, parallel relation, and a layer of substantially straight, self-sustaining, stranded brush material interposed and held tightly clamped between the faces of such straight, parallel wire portions, the component strands being disposed in substantially parallel relation transversely of such clampin wire portions, and the outer edges of such layer being at an angle to the stem axis.

4. A brush formed of opposed, elongated members, twisted together to form a stem except for a limited extent where such members are left in straight, closely pressed, parallel relation, and a flat layer of substantially straight, self-sustaining, stranded brush material interposed and held tightly clamped between such straight portions of said members, the component strands being disposed in substantially parallel relation transversely of such clamping wire portions, and the edges of said layer of brush material being trimmed to a contour angularly related to such stem of said brush.

5. A brush comprising a holder having an aperture therein with a slot intersecting such aperture crosswise of said holder, and a replaceable brush element, having a stem extending into such aperture and a flat layer of stranded brush material secured to one end of such stem and extending through such intersecting crosswise slot to provide a brushing face supported by the edges of such slot.

6. A brush comprising a cylindrical holder having a central axial aperture and a crosswise slot intersecting such aperture at one end of said holder, and a replaceable brush element having a stem adapted to extend into such central aperture and a fiat layer of stranded brush material secured to and extending crosswise such stem, such material being received and held in such slot.

7. A brush comprising a stem formed of a. doubled wire, whereof the doubled portions are twisted together to form a stem except for a. limited extent adjacent the point of doubling, Where such wire portions are left in straight, closely pressed, parallel relation, and a layer of substantially straight, self-sustaining, stranded brush material interposed and held between the faces of such straight, parallel wire portions, the component strands being disposed in substantially parallel relation transversely of such clamping wire portions; in combination with a holder having an aperture to receive such stem and a slot intersecting such aperture crosswise of one end of said holder to receive such layer of brush material with the edges thereof projecting beyond said holder.

8. A brush comprising a stem formed of a doubled wire of half-round cross section, the doubled portions having their flat faces opposed and being twisted together to form a stem except for a limited extent adjacent the point of doubling, where such wire portions are left in straight, closely pressed, parallel relation, and a layer of substantially straight, self-sustaining, stranded brush material interposed and held between the faces of such straight, parallel wire portions, the component strands being disposed in substantially parallel relation transversely of such wire portions and the edges of such layer being an angle to the stem axis; in combination with a holder of general cylindrical form having one end tapered, a central bore adapted to receive such stem and a slot at such tapered end intersecting such aperture at one end of said holder to receive such layer of brush material with the edges thereof projecting laterally of and in substantially parallel relation to the tapered end of said holder.

9. In the manufacture of brushes of the twisted wire stem type, the steps which include placing a layer of stranded brush material between the opposed faces of two elongated members, twisting the portions of said members lying beyond the layer of brush material and subjecting such layer to pressure between said members by laterally pressing said members towards each other during such twisting operation whereby such,

layer is clamped between the untwisted portions of said members.

10. In the manufacture of brushes of the twisted wire stem type, the steps which include placing a layer of stranded brush material between the opposed faces of a doubled wire adjacent the point of doubling with the component strands disposed in substantially parallel relation transversely of said wire, subjecting such layer to endwise pressure towards such point, laterally pressing such opposed faces of the wire toward each other whereby such layer is clamped between such faces, and then twisting the remaining portions of the wire together to form a stem.

11. In the manufacture of brushes of the type comprising a body of locally compacted brush material and a retaining member fixed about such locally compacted portion, the steps which include locally compacting a body of brush material intermediately of its ends by application of pressure thereto in excess of the tensile strength of such retaining member, and tightly confining such locally compacted portion of such material within such retaining member to maintain such material thus compacted.

12. In the manufacture of brushes of the twisted stem type, the steps which include placing a layer of brush material between opposed stem elements, applying pressure to such elements to laterally compress such material therebetween, trimming the edges of such compressed layer to desired contour, and then twisting such stem elements to form a helical brush.

10 13. In the manufacture of brushes of the twisted wire stem type, the steps which include placing a layer of stranded brush material between the opposed faces of a doubled wire adjacent the point of doubling with the component strands disposed in substantially parallel relation transversely of said wire, laterally pressing such opposed faces of the wire toward each other whereby such layer is clamped between such faces, and then twisting the remaining portions of the wire together to form a stem.

RUBEN O. PETERSON. VERNON K. CHARVAT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

